The present invention is especially directed to thermoforming machinery of the type in which mold carrying platens are moved cyclically between open and closed positions to differential pressure form parts in heated synthetic plastic webs on a mass production basis. Such machinery includes a female mold into which portions of the plastic web have been moved to conform to the contour of the mold cavity and their shape is such that a positive stripping of the entire web from the mold cavities is a necessity. Applicants are aware of cylinder operated stripper mechanisms, and also mechanically operated stripper mechanisms of the type disclosed in the present assignee's U.S. Pat. No. 3,376,607. The present improved stripper construction is especially directed to a positively acting stripper which is locked to the frame when the molds are in mold closed position, and until the female mold has been withdrawn a predetermined distance prior to being unlatched so that it may accompany the female mold as it continues to withdraw.
A further object of the invention is to provide an economically constructed, more reliable stripper subassembly which may be applied to existing machines in the field, as well as to presently manufactured machinery.